/* ************************************************************************
 * Copyright (c) 2018 Advanced Micro Devices, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * ************************************************************************ */

#include "../../utils/def.hpp"
#include "preconditioner_saddlepoint.hpp"
#include "preconditioner.hpp"
#include "../solver.hpp"

#include "../../base/local_matrix.hpp"

#include "../../base/local_vector.hpp"

#include "../../utils/log.hpp"

#include <complex>

namespace rocalution {

template <class OperatorType, class VectorType, typename ValueType>
DiagJacobiSaddlePointPrecond<OperatorType, VectorType, ValueType>::DiagJacobiSaddlePointPrecond()
{
    log_debug(this,
              "DiagJacobiSaddlePointPrecond::DiagJacobiSaddlePointPrecond()",
              "default constructor");

    this->size_ = 0;

    this->K_solver_ = NULL;
    this->S_solver_ = NULL;

    this->K_nrow_ = 0;
    this->K_nnz_  = 0;
}

template <class OperatorType, class VectorType, typename ValueType>
DiagJacobiSaddlePointPrecond<OperatorType, VectorType, ValueType>::~DiagJacobiSaddlePointPrecond()
{
    log_debug(this, "DiagJacobiSaddlePointPrecond::~DiagJacobiSaddlePointPrecond()", "destructor");

    this->Clear();
}

template <class OperatorType, class VectorType, typename ValueType>
void DiagJacobiSaddlePointPrecond<OperatorType, VectorType, ValueType>::Clear(void)
{
    log_debug(this, "DiagJacobiSaddlePointPrecond::Clear()", this->build_);

    if(this->build_ == true)
    {
        this->A_.Clear();
        this->K_.Clear();
        this->S_.Clear();

        this->A_.ConvertToCSR();
        this->K_.ConvertToCSR();
        this->S_.ConvertToCSR();

        this->K_nrow_ = 0;
        this->K_nnz_  = 0;

        this->x_.Clear();
        this->x_1_.Clear();
        this->x_2_.Clear();

        this->rhs_.Clear();
        this->rhs_1_.Clear();
        this->rhs_1_.Clear();

        this->permutation_.Clear();

        if(this->K_solver_ != NULL)
        {
            this->K_solver_->Clear();
        }

        if(this->S_solver_ != NULL)
        {
            this->S_solver_->Clear();
        }

        this->size_ = 0;

        this->K_solver_ = NULL;
        this->S_solver_ = NULL;

        this->build_ = false;
    }
}

template <class OperatorType, class VectorType, typename ValueType>
void DiagJacobiSaddlePointPrecond<OperatorType, VectorType, ValueType>::Print(void) const
{
    if(this->build_ == true)
    {
        LOG_INFO("DiagJacobiSaddlePointPrecond preconditioner with "
                 << " ; S solver:");

        this->S_solver_->Print();

        LOG_INFO("and K solver:")
        this->K_solver_->Print();
    }
    else
    {
        LOG_INFO("DiagJacobiSaddlePointPrecond (I)LU preconditioner");
    }
}

template <class OperatorType, class VectorType, typename ValueType>
void DiagJacobiSaddlePointPrecond<OperatorType, VectorType, ValueType>::Set(
    Solver<OperatorType, VectorType, ValueType>& K_Solver,
    Solver<OperatorType, VectorType, ValueType>& S_Solver)
{
    log_debug(this,
              "DiagJacobiSaddlePointPrecond::Set()",
              (const void*&)K_Solver,
              (const void*&)S_Solver);

    this->K_solver_ = &K_Solver;
    this->S_solver_ = &S_Solver;
}

template <class OperatorType, class VectorType, typename ValueType>
void DiagJacobiSaddlePointPrecond<OperatorType, VectorType, ValueType>::Build(void)
{
    log_debug(this, "DiagJacobiSaddlePointPrecond::Build()", this->build_, " #*# begin");

    assert(this->build_ == false);
    this->build_ = true;

    assert(this->op_ != NULL);
    assert(this->K_solver_ != NULL);
    assert(this->S_solver_ != NULL);

    this->A_.CloneBackend(*this->op_);
    this->K_.CloneBackend(*this->op_);
    this->S_.CloneBackend(*this->op_);

    this->x_.CloneBackend(*this->op_);
    this->x_1_.CloneBackend(*this->op_);
    this->x_2_.CloneBackend(*this->op_);

    this->rhs_.CloneBackend(*this->op_);
    this->rhs_1_.CloneBackend(*this->op_);
    this->rhs_1_.CloneBackend(*this->op_);

    this->permutation_.CloneBackend(this->x_);

    this->A_.CloneFrom(*this->op_);

    //  this->A_.ConvertToCSR();

    this->A_.ZeroBlockPermutation(this->size_, &this->permutation_);

    this->A_.Permute(this->permutation_);

    this->A_.ExtractSubMatrix(0, 0, this->size_, this->size_, &this->K_);

    OperatorType E, F;
    VectorType inv_K;

    E.CloneBackend(*this->op_);
    F.CloneBackend(*this->op_);
    inv_K.CloneBackend(*this->op_);

    this->A_.ExtractSubMatrix(0, this->size_, this->size_, this->A_.GetLocalN() - this->size_, &F);

    this->A_.ExtractSubMatrix(this->size_, 0, this->A_.GetLocalM() - this->size_, this->size_, &E);

    this->A_.Clear();

    // Construct solver for K
    this->K_solver_->SetOperator(this->K_);
    this->K_solver_->Build();

    // Construct solver for S
    // inv_K = inv(diag(K))
    this->K_.ExtractInverseDiagonal(&inv_K);

    // E = E * inv(diag(K))
    E.DiagonalMatrixMult(inv_K);

    // S = E * F
    this->S_.MatrixMult(E, F);

    this->S_solver_->SetOperator(this->S_);
    this->S_solver_->Build();

    this->x_.CloneBackend(*this->op_);
    this->x_.Allocate("Permuted solution vector", this->op_->GetM());

    this->rhs_.CloneBackend(*this->op_);
    this->rhs_.Allocate("Permuted RHS vector", this->op_->GetM());

    this->x_1_.CloneBackend(*this->op_);
    this->x_1_.Allocate("Permuted solution vector", this->size_);

    this->x_2_.CloneBackend(*this->op_);
    this->x_2_.Allocate("Permuted solution vector", this->op_->GetM() - this->size_);

    this->rhs_1_.CloneBackend(*this->op_);
    this->rhs_1_.Allocate("Permuted solution vector", this->size_);

    this->rhs_2_.CloneBackend(*this->op_);
    this->rhs_2_.Allocate("Permuted solution vector", this->op_->GetM() - this->size_);

    log_debug(this, "DiagJacobiSaddlePointPrecond::Build()", this->build_, " #*# end");
}

template <class OperatorType, class VectorType, typename ValueType>
void DiagJacobiSaddlePointPrecond<OperatorType, VectorType, ValueType>::Solve(const VectorType& rhs,
                                                                              VectorType* x)
{
    log_debug(this, "DiagJacobiSaddlePointPrecond::Solve()", " #*# begin", (const void*&)rhs, x);

    assert(this->build_ == true);

    this->rhs_.CopyFromPermute(rhs, this->permutation_);

    this->rhs_1_.CopyFrom(this->rhs_, 0, 0, this->size_);

    this->rhs_2_.CopyFrom(this->rhs_, this->size_, 0, this->rhs_.GetLocalSize() - this->size_);

    // Solve the first (K) block
    this->K_solver_->SolveZeroSol(this->rhs_1_, &this->x_1_);

    // Solve the second (S) block
    this->S_solver_->SolveZeroSol(this->rhs_2_, &this->x_2_);

    // Copy back
    this->x_.CopyFrom(this->x_1_, 0, 0, this->size_);

    this->x_.CopyFrom(this->x_2_, 0, this->size_, this->rhs_.GetLocalSize() - this->size_);

    x->CopyFromPermuteBackward(this->x_, this->permutation_);

    log_debug(this, "DiagJacobiSaddlePointPrecond::Solve()", " #*# end");
}

template <class OperatorType, class VectorType, typename ValueType>
void DiagJacobiSaddlePointPrecond<OperatorType, VectorType, ValueType>::MoveToHostLocalData_(void)
{
    log_debug(this, "DiagJacobiSaddlePointPrecond::MoveToHostLocalData_()", this->build_);

    this->A_.MoveToHost();
    this->K_.MoveToHost();
    this->S_.MoveToHost();

    this->x_.MoveToHost();
    this->x_1_.MoveToHost();
    this->x_2_.MoveToHost();

    this->rhs_.MoveToHost();
    this->rhs_1_.MoveToHost();
    this->rhs_2_.MoveToHost();

    this->permutation_.MoveToHost();

    if(this->K_solver_ != NULL)
    {
        this->K_solver_->MoveToHost();
    }

    if(this->S_solver_ != NULL)
    {
        this->S_solver_->MoveToHost();
    }
}

template <class OperatorType, class VectorType, typename ValueType>
void DiagJacobiSaddlePointPrecond<OperatorType, VectorType, ValueType>::MoveToAcceleratorLocalData_(
    void)
{
    log_debug(this, "DiagJacobiSaddlePointPrecond::MoveToAcceleratorLocalData_()", this->build_);

    this->A_.MoveToAccelerator();
    this->K_.MoveToAccelerator();
    this->S_.MoveToAccelerator();

    this->x_.MoveToAccelerator();
    this->x_1_.MoveToAccelerator();
    this->x_2_.MoveToAccelerator();

    this->rhs_.MoveToAccelerator();
    this->rhs_1_.MoveToAccelerator();
    this->rhs_2_.MoveToAccelerator();

    this->permutation_.MoveToAccelerator();

    if(this->K_solver_ != NULL)
    {
        this->K_solver_->MoveToAccelerator();
    }

    if(this->S_solver_ != NULL)
    {
        this->S_solver_->MoveToAccelerator();
    }
}

template class DiagJacobiSaddlePointPrecond<LocalMatrix<double>, LocalVector<double>, double>;
template class DiagJacobiSaddlePointPrecond<LocalMatrix<float>, LocalVector<float>, float>;
#ifdef SUPPORT_COMPLEX
template class DiagJacobiSaddlePointPrecond<LocalMatrix<std::complex<double>>,
                                            LocalVector<std::complex<double>>,
                                            std::complex<double>>;
template class DiagJacobiSaddlePointPrecond<LocalMatrix<std::complex<float>>,
                                            LocalVector<std::complex<float>>,
                                            std::complex<float>>;
#endif

} // namespace rocalution
